Radar Cross Section Based Passive Wireless Sensor for Volatile Sensing

This paper presents a radar cross section-based passive, wireless acidic/basic volatile sensor with a built-in reference enabling differential sensing capabilities. The concept of a two-electrode gas sensing scheme coupled with indirect capacitive transduction is shown. The low cost, passive nature and volatile sensing ability makes the sensor suitable for food quality monitoring applications. Simulation results and preliminary measurements of the proposed sensing element are presented. Simulations indicate a sensitivity of 188MHz change in resonant frequency for 1pF change in capacitance.